High resolution melting curve analysis for rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants.

Since the emergence of the original Wuhan SARS-CoV-2 strain, several new variants of the virus have emerged. Alpha, Beta, Gamma, Delta and the most recent Omicron variants have been introduced during this pandemic. Several methods including, but not restricted to, allele-specific PCR, ligation with rolling circle amplification and real-time PCR with allele-specific probes are able to detect mutations as low as a single nucleotide polymorphism. High-resolution melting curve analysis is ano-ther technique to assess any mutations in a nucleic acid chain. Confirmed samples with SARS-CoV-2 infection were subjected to variant identification using a de novo-designed HRM assay. In order to select for mutations with the highest effect on Tm of the amplicon, deletion mutations of NSP6 (Del 3675-3677), and S1 (Del 144) were chosen for HRM analysis. HRM analysis for the amplicon of the primer set-1 (NSP6) resulted in Tm differences of -0.39°C, +0.4°C, and -0.6°C between Alpha, Delta, and Omicron variants, respectively, in comparison to the original Wuhan strain. Moreover, HRM analysis of the amplification performed by primer set-2 (S1) led to Tm differences of +0.32°C, -0.26°C, and +0.24°C between Alpha, Delta, and Omicron variants, respectively, in comparison to original Wuhan strain. The test was able to specify each sample to its variant group with more than 90 percent of confidence. The results obtained in this study demonstrate that using a single closed-tube strategy with a HRM-equipped machine, screening new variants of the virus is possible in a fast and reliable way. Keywords: high resolution melting; SARS coronavirus 2; mutation; variant; genotyping.

Cases of Mediterranean spotted fever in southeast of Iran.

In this study the clinical manifestations, laboratory findings, and management of five patients diagnosed with Mediterranean spotted fever (MSF) from southeast of Iran are presented. All patients but one had recent tick-bite histories which were noticeable as black eschars (tache noire). Patients' samples were tested by real-time PCR and serology (IFA). The disease was confirmed by fourfold rising of IgG antibodies against Rickettsia conorii. This is the first report of MSF cases in Iran.

Prevalence of adeno-associated virus and human papillomavirus DNA in Iranian women with and without cervical cancer.

There is plenty of substantial evidence to support anti-tumor activity of viruses. Adeno-associated virus (AAV) may interact with human papillomavirus (HPV) to modify the risk of cervical neoplasia. The seroprevalence of AAV among women with cervical cancer has been reported to be lower than healthy ones. In spite of this finding, detection of AAV DNA in cervical biopsies does not entirely support the inverse association between AAV seropositivity and cervical cancer. This association is still controversial and requires more thorough evaluation in different countries. The aim of this case-control study was to find the prevalence of AAV and HPV DNA sequences in Iranian women with and without cervical cancer to assess the probable association of AAV infection and cervical cancer. In this study, paraffin-embedded tissue samples of 61 cervical cancer cases and 50 healthy controls (HCs) were investigated for AAV and HPV DNA by semi-nested and nested PCRs respectively. AAV DNA was detected in 7 cases (14%) of HCs and 9 specimens (14.8%) of case group. According to the branching in the phylogenetic tree, AAV2 was the only type detected in this study. Moreover, HPV DNA was detected in 8 cases (16%) of HCs and 44 specimens (72.13%) of case group. In conclusion, a low proportion of cervical biopsies from Iranian women contained AAV-2 genome. No significant difference in correlation between HPV and cervical cancer in presence or absence of AAV genome in cervix was found.